This invention relates generally to the handling and transfer of small articles, such-as computer chips and the like from a first location to a second location, and more particularly to an improved multiple pickup head construction which provides for the transfer of as many as four individual workpieces between a first matrix and a second matrix.
Pickup units of this type are known in the art, and usually include a reciprocating spindle having vacuum means extending through a hollow channel to enable the workpiece to be engaged and subsequently disengaged at the release location.
The semi-conductor industry has an ever present need for high-speed pick and place of semi-conductor chips. This is particularly true in at least three areas in semi-conductor direction and use, including inspection, singulation, and circuit board population.
In general, these three areas all require the picking and placing of chips during processing. Until recently, this was accomplished using a single head unit. In my earlier presently pending provisional application, Serial No. 60/013,239, there is disclosed a dual head construction which, in effect, doubles the speed of pick and place relative to a single head. The presently disclosed quadruple head construction quadruples the speed of picking and placing as compared to a single head.
As an example, one operation is an inspection system for checking chips for visual flaws. With a dual head construction it is typically possible to process six thousand to eight thousand chips per hour. The same machine with a quadruple head may process twelve thousand to sixteen thousand chips per hour. Since these systems are very costly, the advantages of increased speed are obvious.
In addition to the need for speed, the other requirement centers about programmability for varying matrix configurations encountered in chip media, i.e. matrix trays used during semi-production, tape and reel used to ship chips, and strips or wafers that are singulated to yield individual chips from a batch.
During some manufacturing operations, it is desirable to arrange for deposition of articles on a place matrix such that the deposited articles are arranged in single line fashion to permit ready and serial removal of defective articles on inspection.
The present invention is directed to a means for positioning quadruple pick and place probes in a programmable matrix structure. Positioning includes an XY axis capability for the matrix, a Z axis capability to extend or retract individual probes, and a capability to rotate individual probes. Each of the four probes supports a vacuum cup with a through the spindle passage to apply vacuum to a chip or other object if required. The disclosed device could be used as an end of an arm effector for a robot enabling it to move four objects simultaneously from one matrix location to another.
In several disclosed embodiments, the head units are arranged such that the spindles each have an axis lying in a common vertical plane so that articles deposited on the place matrix are arranged in in-line fashion to permit ready inspection and possible removal if faulty.